Probing the kinetic energy-release dynamics of H-atom products from the gas-phase reaction of O(3P) with vinyl radical C2H3

Su Chan Jang, Jong-Ho Choi

Research output: Contribution to journalArticle

2 Citations (Scopus)

Abstract

The gas-phase radical-radical reaction dynamics of ground-state atomic oxygen O(3P) with vinyl radicals C2H3 has been studied by combining the results of vacuum-ultraviolet laser-induced fluorescence spectroscopy in a crossed beam configuration with ab initio calculations. The two radical reactants O(3P) and C2H3 were produced by photolysis of NO2 and supersonic flash pyrolysis of C2H3I, respectively. Doppler profile analysis of the kinetic energy release of the nascent H-atom products from the title reaction O(3P) + C2H3 - H(2S) + CH2CO (ketene) revealed that the average translational energy of the products and the average fraction of the total available energy were 7.03 ± 0.30 kcal mol-1 and 7.2%. The empirical data combined with CBS-QB3 level ab initio theory and statistical calculations demonstrated that the title oxygen-hydrogen exchange reaction is a major reaction channel, through an addition-elimination mechanism involving the formation of a short-lived, dynamical complex on the doublet potential energy surface. On the basis of systematic comparison with several exchange reactions of hydrocarbon radicals, the observed kinetic energy release can be explained in terms of the weak impulse at the moment of decomposition in the loose transition state with a product-like geometry and a small reverse barrier along the exit channel.

Original languageEnglish
Pages (from-to)23679-23685
Number of pages7
JournalPhysical Chemistry Chemical Physics
Volume16
Issue number43
DOIs
Publication statusPublished - 2014 Nov 21

Fingerprint

vinyl radical
Kinetic energy
Gases
kinetic energy
vapor phases
Oxygen
Ultraviolet lasers
Atoms
Potential energy surfaces
Photolysis
Fluorescence Spectrometry
Fluorescence spectroscopy
products
Vacuum
Hydrocarbons
Ground state
atoms
Hydrogen
Lasers
Pyrolysis

Cite this

Probing the kinetic energy-release dynamics of H-atom products from the gas-phase reaction of O(3P) with vinyl radical C2H3 . / Jang, Su Chan; Choi, Jong-Ho.

In: Physical Chemistry Chemical Physics, Vol. 16, No. 43, 21.11.2014, p. 23679-23685.

Research output: Contribution to journalArticle

@article{19c942125d4648df99f431283551b010,
title = "Probing the kinetic energy-release dynamics of H-atom products from the gas-phase reaction of O(3P) with vinyl radical C2H3",
abstract = "The gas-phase radical-radical reaction dynamics of ground-state atomic oxygen O(3P) with vinyl radicals C2H3 has been studied by combining the results of vacuum-ultraviolet laser-induced fluorescence spectroscopy in a crossed beam configuration with ab initio calculations. The two radical reactants O(3P) and C2H3 were produced by photolysis of NO2 and supersonic flash pyrolysis of C2H3I, respectively. Doppler profile analysis of the kinetic energy release of the nascent H-atom products from the title reaction O(3P) + C2H3 - H(2S) + CH2CO (ketene) revealed that the average translational energy of the products and the average fraction of the total available energy were 7.03 ± 0.30 kcal mol-1 and 7.2{\%}. The empirical data combined with CBS-QB3 level ab initio theory and statistical calculations demonstrated that the title oxygen-hydrogen exchange reaction is a major reaction channel, through an addition-elimination mechanism involving the formation of a short-lived, dynamical complex on the doublet potential energy surface. On the basis of systematic comparison with several exchange reactions of hydrocarbon radicals, the observed kinetic energy release can be explained in terms of the weak impulse at the moment of decomposition in the loose transition state with a product-like geometry and a small reverse barrier along the exit channel.",
author = "Jang, {Su Chan} and Jong-Ho Choi",
year = "2014",
month = "11",
day = "21",
doi = "10.1039/c4cp03046j",
language = "English",
volume = "16",
pages = "23679--23685",
journal = "Physical Chemistry Chemical Physics",
issn = "1463-9076",
publisher = "Royal Society of Chemistry",
number = "43",

}

TY - JOUR

T1 - Probing the kinetic energy-release dynamics of H-atom products from the gas-phase reaction of O(3P) with vinyl radical C2H3

AU - Jang, Su Chan

AU - Choi, Jong-Ho

PY - 2014/11/21

Y1 - 2014/11/21

N2 - The gas-phase radical-radical reaction dynamics of ground-state atomic oxygen O(3P) with vinyl radicals C2H3 has been studied by combining the results of vacuum-ultraviolet laser-induced fluorescence spectroscopy in a crossed beam configuration with ab initio calculations. The two radical reactants O(3P) and C2H3 were produced by photolysis of NO2 and supersonic flash pyrolysis of C2H3I, respectively. Doppler profile analysis of the kinetic energy release of the nascent H-atom products from the title reaction O(3P) + C2H3 - H(2S) + CH2CO (ketene) revealed that the average translational energy of the products and the average fraction of the total available energy were 7.03 ± 0.30 kcal mol-1 and 7.2%. The empirical data combined with CBS-QB3 level ab initio theory and statistical calculations demonstrated that the title oxygen-hydrogen exchange reaction is a major reaction channel, through an addition-elimination mechanism involving the formation of a short-lived, dynamical complex on the doublet potential energy surface. On the basis of systematic comparison with several exchange reactions of hydrocarbon radicals, the observed kinetic energy release can be explained in terms of the weak impulse at the moment of decomposition in the loose transition state with a product-like geometry and a small reverse barrier along the exit channel.

AB - The gas-phase radical-radical reaction dynamics of ground-state atomic oxygen O(3P) with vinyl radicals C2H3 has been studied by combining the results of vacuum-ultraviolet laser-induced fluorescence spectroscopy in a crossed beam configuration with ab initio calculations. The two radical reactants O(3P) and C2H3 were produced by photolysis of NO2 and supersonic flash pyrolysis of C2H3I, respectively. Doppler profile analysis of the kinetic energy release of the nascent H-atom products from the title reaction O(3P) + C2H3 - H(2S) + CH2CO (ketene) revealed that the average translational energy of the products and the average fraction of the total available energy were 7.03 ± 0.30 kcal mol-1 and 7.2%. The empirical data combined with CBS-QB3 level ab initio theory and statistical calculations demonstrated that the title oxygen-hydrogen exchange reaction is a major reaction channel, through an addition-elimination mechanism involving the formation of a short-lived, dynamical complex on the doublet potential energy surface. On the basis of systematic comparison with several exchange reactions of hydrocarbon radicals, the observed kinetic energy release can be explained in terms of the weak impulse at the moment of decomposition in the loose transition state with a product-like geometry and a small reverse barrier along the exit channel.

UR - http://www.scopus.com/inward/record.url?scp=84908005495&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84908005495&partnerID=8YFLogxK

U2 - 10.1039/c4cp03046j

DO - 10.1039/c4cp03046j

M3 - Article

VL - 16

SP - 23679

EP - 23685

JO - Physical Chemistry Chemical Physics

JF - Physical Chemistry Chemical Physics

SN - 1463-9076

IS - 43

ER -